vehicle moving on wheels: such as. a archaic : carriage, chariot. b : a vehicle designed to move on rails (as of a railroad) The train has 20 cars. c : automobile traveled to Boston by car. vehicle moving on wheels: such as. a archaic : carriage, chariot. b : a vehicle designed to move on rails (as of a railroad) The train has 20 cars. c : automobile traveled to Boston by car.